Engine



Nov. 24, 1936. w. G. GERNANDT ENGINE Filed March 6,- 1931 2 Sheets-Sheet1 INVENToR. WAL/.po 6 GEMMA/a7' "Y -wmmmr ATTORNEY W. G. GERNANDT ENGINENov. 24,- 1936.

l Filed March s, 1931 2 Sheets-Sheetl 2l ATTORNEY Patented Nov. 24, 19364mrlazu'r ori-ICE ENGINE Waldo G. Gernandt, Hayward, Calif.

ApplicationMarch 6, 1931, Serial No. 520,564 2 Claims. (c1. 12s-3s) Thisinvention relates to Diesel engines and more particularly to fuelinjection units for engines of `the Diesel type wherein the compressorunit is a complete assembly and adapted to be installed in detachablerelation to the engine.

'I'he present application is an improvement on my copending applicationNo. 499,636, led December 3, 1930, issued Jan. 1, 1935, as Patent No.

1,986,674, and in certain respects, differs thereif from bythe manner inwhich the compressor discharge valves are operated.

An object of the invention is to provide a fuel injection unit that isadapted to entrap a portion of the fluid products of combustion from acylinder of the engine during the expansion stroke fand subsequentlyintroducing it tothe compressor wherein it is additionally compressedand discharged to the engine, the purpose of the engine charge being toaugment the primary charge of fuel mixture which has been drawn into thecompressor from, another source.

A feature of the invention relates to the operation of the dischargevalve of the unit, which in the illustrative embodiment, is not onlyopened to discharge fuel into the engine cylinder, but is also opened asecondftime in the same engine cycle to permit the high pressure gaseswithin the engine cylinder to be forced back into the compressor andfurther compressed for discharge into. a subsequent ring cylinder.

Other objects and features of the invention will be apparent from thefollowing description of a preferred embodiment of the invention which`I have illustrated in the followingv drawings in which:

Figure 1 is a vertical sectional view of the compressor unit; and

Figure 2 is a side elevation partly in section, of the injection unitshown in Figure 1; and

Figure 3 is a top plan view of the compressor with the head removed.

Referring to the drawings, I is a crank case to crank shaft 4 is rotatedat twice the speed of the y y driven shaft 8.

Above the drive shaft s is mounted the @am shaft I4, which is driven byshaft 8 at one-half the speed of shaft 8, throughgears I6 and I8.

Cam shaft I4 is provided with a series of four cams which are arrangedin angularly spaced intervals of,90, each cam having a pair of spacedlobes 20 and 2|, whereby the respective valves 22 are lifted twice ineach revolution by arms 24 pivotally mounted on case I. Each of thevalves is adapted to control an opening 28 that leads to y a conduitv 30in communication with a fitting 32 leading to the working cylinders ofthe engine (not shown) to which the injection unit is secured.`

Leading from the upper end of the compressor cylinder is a transversepassage 34 which intersects a longitudinal passage 36 which communicateswith the chamber 38 (which is) provided underneath each of therespective valves. The passage 36 is preferably drilled through one wallof the cylinder and has its outer end closed by screw 31. An inletpassage 40 leads from a source of Isupply of exhaust'gasor opensdirectly to the atmosphere, depending upon whether it is desired 'tocharge the engine with a mixture of fuel and inert gas, or a mixture offuel and atmospheric air.

The passage 4I, between inlet 40 and the crank case I, is unobstructedand gas may freely enter the crank case because of the suction producedtherein by the outward or upward movement of the piston 3. The Venturitube 44, in which is mounted the fuel jet 46, is located adjacent thespring loaded valve 48 and the gas used for atomizing the fuel onlytraverses the fuel jet opening on its way fromthe crank case to thecylinder.

The fuel is fed to jet 46 by means of a fuel pump 50 having an inlet 52and an outlet conduit` 54 which leads to the jet 46 by passageway 56formed in the cylinder casting. The opening of the fuel jet iscontrolled by needle valve 58, whichis controlled by a cam rotatablymounted in bearing 62, lsecured to the valve cover 64 by screws 66, theshaft being rotated to raise and depress the. needle valve by a lever68.

In the operation of the invention, exhaust gas or air is drawn into thecrank case by the upward movement of the piston 3, which upondescending, draws the gas upwardly through passage 4I past the fuel jet46 from which it draws a supply of fuel controlled by the opening of theneedle valve 58, and through the valve 48 into the compressor cylinder.The upward movement of the piston 3 compresses the fuel mixture withinthe cylinder until one of the fuel valves 22 is opened by the cam shaft,whereupon it flows to the working cylinder of the engine thatcorresponds to the respective distributor valve of the injection unit.

The distributor valves 22 are operated by the cam shaft I4, whichrotates at half engine speed and therefore, one of. the distributorvalves is opened twice during each'revolution against the resistance ofspring 23 by cam lobes 2|) and 2|. The arrangement of a -singlecompressor cylinder driven at twice engine speed and a distributor valvemechanism which is' driven at one-half the engine speed, permits the useof a single compressor cylinder for a four cylinder engine, and eachengine charge is of the same volume and quality, for any leakage whichmay develop in the compressor will affect all of the engine cylindersequally. Cam lobe 2| is arranged in a clockwise direction with respectto lobe 20 and in position to lift valve 22 a second time after aboutdegrees of cam rotation, or degrees'h of engine rotation. The lifting ofthe valveluy the cam lobe 2| places cylinder 3 in communication with theengine cylinder during its combustion stroke and permits the highpressure gases to enter the compressor cylinder and augment the chargewhich has been previously drawn into the compressor from the crank case.On the up stroke'of the compressor piston 3, the combined charge ofmixture from the crank case, and high pressure gases from the enginecylinder will be introduced into the next cylinder firing in the regularrotation and the charge will be under a considerably higher pressurethan it would have been if the charge consisted only of the mixturedrawn into the compressor from the crank case.

While I have illustrated and described a preferred embodiment of myinvention, it is understood that this showing and description areillustrative only and that I do not regard the invention as limited tothe forms shown and described, except by the terms of the followingclaims.

I claim:

1. A fuel injection unit for a multi-cylinder engine, comprising asingle compressor cylinder, a piston in said cylinder, a plurality ofsuccessively operated valves controlling the communication between saidcylinder and individual engine cylinders, and means for operating eachof said valves at two different positions of said piston in one pumpingcycle thereof, one for the ejection of fuel and the other to take inengine gases.

2. A fuel injection unit for a multi-cylinder engine, comprising asingle compressor cylinder, a. piston in said cylinder, a plurality ofsuccessively operated valves controlling the communication between saidcylinder and individual engine cylinders, and a plurality of angularlyspaced cams for'opening each valve at two different piston positions,one for the ejection of fuel and the other to take in engine gases.

wALDo G. GEaNANDT.

